Reinforced-concrete pile for marine work.



Sill

lrlliWlS Jkt. EERGUSQN, @03F PHI'LDELPHA, PENNSYLVANIA.

LRENEGMTLDMCNCRETE IEILE FOR MARINE WRK.

specialistica or Letters rarest. patented ppb., gp, 11mg,

Application filed lttaroh 10, 191'?. Serial No; 153,981.

.lb all 'eoliche t may concern:

Be it known that l, LEWIS. E. FERGUSON, a citizen of the United States," residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful improvements in Reinforced-Concrete Piles for Marine Work; y and l hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form part of this specificaM tion. v `'l'fhis invention relates to the construction of reinforced concrete piles, columns and the like for marine work and is particularly designed for use in the manufacture of piles to be nsed in or near salt water, and where auch piles will be exposed to the action of damp salt air.

ll have discovered that metal reinforced concrete piles as heretofore constructed when used forymarine work crack and spall, and rapidly lose their strength and become dangerous because of their disintegration. Educh disintegrationl have found occurs chiexdy, if not solely, in reinforced concreto piles and the like used in foundations for marine structures in or near' salt water.

This disintegration of the piles l have fojund follows the line of the reinforcement and 4always starts above the low water line and is most extensive about the high water.

line; and such cracking and spalling is due to oxidization of the reinforcement; as I further found that the portions nof the piles which are buried or submerged are not detrimentally adected as are the exposed ortions ofthe piles above low water. his disintegration has been attributed heretofore to causes other than the true one.

lt has heretofore beenconsidered by experts in concrete construction that the reinforcement should be embedded only an inch or two in the concrete, and that it would be secure from oxidization and elemental action and that-any greater'thickness of protective coatingfor the reinforcing bars would be unnecessary. andl undesirab e. Butl have `@discovered that practically all the reinforced 4 concrete piles orvfoundation columns in concrete structures along the Atlantic and Pacific coasts are deteriorating and giving way on account of the cracking and spalling l have discovered that such cracking and spelling and disintegration of the piles can be prevented orindeinitely retarded by so arranging the metal reinforcing that the portlons thereof within the exposed portions of the piles, or that portion above low water when the pile is in situ, will be embedded in the concrete to a much greater' depth than the portion ofthe reinforcing 1n the submerged part of the pile, and by means of my invention there is obtained a layer of concrete preferably four or more inches in thickness between the metal reinforcement and the exterior surface of the pile. The great value of my invention will be appreciated by those who understand the diiliculty or impossibility of repairing or replacing disintegrated sections in the exposed portions of reinforced concrete piles.

ln utilizing my invention, in the preferred manner, the reinforcing members in the piles are bent or 'deflected inwardly at a point which will be near the low water mark when the pile is situ, so that the reinforciup,l members in the exposed portion of the pi ey shell be protected by a much greater thicknessof concrete than the portions of the reinforcing in the submerged or buried part of the pile. This constructionl is par-- ticularly eliicient where it is'desiredior necessary to keep the pile of a substantially uniform diameterthroughout. Incases where i-t is feasible to enlarge the diameter of the exposed portion of thc pile sufficiently to give the necessary thickness of concrete to protect the reinforcing, the reinforcing might extend straight throughout the pile.

l will explain the invention with reference to the accompanying drawings in which:

Figure l is a sectional elevation of a reinforced concretey pile constructed in accordance with the invention.

Figs. tE2 and 3 are transverse sections of such pile, taken respectively on lines 2-2 and lf3-8 Fig. 1.

Fig. 4l is a vertical section-through a modilied form of pile; and

Figs. 5 and 6 are transverse sections of such pile, taken respectively on lines 5 5 and 6-6 F ig. ed

The concrete pile may be of any desired form and dimension; as shown in Figs. 1 to 3 of the drawings the pile 1 may be formed. in the usual manner of concrete, and is re1nforced by a series of longitudinally disposed metal members or bars 2, with or .without spiral Wrappings or hoops, which extend throughout the length of the pile. Heretofore in making piles such reinforcing bars have been embedded only from one topossibly two inches in the pile. A greater depth than this is considered unnecessary and undesirable, as customarily the strength of the pile is calculated on the cross sectional area bounded by the rods. While this is satisfactory for submerged concrete Work, and in the submerged or buried portions of the pile, yet the exposed portions of such piles,

when used in or near salt Water, spall and disintegrate as above stated; and this is the direct cause of a great deal of trouble inconcrete structures heretofore constructed.

in carrying out my invention, the reinforcing members 2 for the pile are bent or converged inwardly as shown at 2a at the point that will be near mean lovv Water when the pile is in situ, and `then continued up- Wardly parallel as indicated at 2b Within the exposed or upper portion of the pile, above low Water when in situ. By this arrangement the portion of the reinforcing in the exposed portion of the pile is embedded to a much greater depth in the concrete than the portion of the reinforcing in the lower buried or submerged part of the pile; consider it preferable to have the upper portion of the reinforcing embedded to a depth of 'at least approximately four inches-in the concrete; for the-chlorin in the air will eventually penetrate even the best concrete piles as novv constructed for a depth of one or two inchesand reach and attack the metal reinforcement and corrode same thereby producing the dangerous spalling, cracking and disintegration of the piles above referred to. But my having the members of the reinforcing in the exposed portion of the pile covered by an exterior layer of approximately four inches or more of concrete the reinforcingk will be indefinitely thoroughly' protected from the action of the damp air, and thellife of the pile will be indefinitely prolonged and its practical value greatly enhanced.

ln the construction shown in Fig. l the lower or submerged portion of the pile may be formed as usual, and the reinforcing bars 2 can extend directly throughout the length thereof, and arranged as in the lower portieri of the pile shown in Fig. l; but the upper exposed portion of the pile is enlarged in diameter so as to thicken the concrete layer exterior to the reinforcing to a depth of approximately four or more inches.

ln' such construction," as shown in Fig. 4, the enlarged portion of the pile should begin at a point near low Water level, as indicated at l, and the enlarged portion should extend throughout the upper or exposed portion of the pile above low Water when in situ, as indicated at l in Figs. 4 and 6.

If desired the reinforcing members and the pile may be further strengthened by bonding hoops or Wire 4 spirally Wrapped around the reinforcin bars7 as indicated in Figs. l and 4 o f the rawings.

The essentially novel feature of the invention is protecting the reinforcing members in the upper or exposed portion of the pile above low water mark by an extra external thickness -of concrete approximately four or more inches in thickness and sufficient to greatly retard or entirely prevent the action of damp salt air upon the portion of the reinforcement extending Within the exposed portion of the pile above mean low Water. Such thickness of concrete has heretofore been considered unnecessary and even detrimental as regards the strength of the pile; but I employ'such an extra thickness of concrete for an entirely different and novel purpose to wit, to protect the metal reinforcement against deterioration or oxidization by the action of the sea spray and salt air, which has heretofore and is now causing rapid disintegration of concrete piles and columns in foundations of marine structures as heretofore constructed where such piles and foundations are subjected to sea spray' and salt air; which disintegration is caused by the oxidizing or chemical action of the moist sea air containing chlorin upon the embedded metal renforcement. This action will penetrate to a depth of one or two inches in the concrete of even the very finest quality, which is sufficient to enable it to attack and destroy the metal reinforcement as heretofore arranged in piles constructed in accordance With the at present accepted best engineering methods, but which action Will be prevented by the use ofmy invention.

What I claim is:

l. A concrete pile for marine work having a plurality of longitudinally disposed reinforcing inetal members embedded therein, the parts of said reinforcin members in the portion of the pile above 0W Water being protected by an external layer of concrete approximately four inches thick; and being much farther removed from the exterior surface of the pile than are the parts of the reinforcing members in the lower or submerged portion of the pile.

S. A reinforced concrete pile for marine structures having a plurality of longitudinally disposed metal reinforcing bars extending throughout its length, the parts of the l" 3s Within the upper part of the pile exposed to the atmosphere above low Water when in situ being embedded in the concrete to a much greater depth than usual, and to a greater depth than are the parts of the bars in the lower or submerged portion of the pile.

3. A reinforced concrete pile for marine Work having metal reinforcing embedded meneer i a, point below the part of the pile exposed to the atmosphere when n situ so that the portion of the reinforcing in the 1portion o the' pile above low Water is much more deeply embedded in the concrete and is protected by a much 'thicker layer of concrete tban'is the .portion of the reinforcing within the lower or submerged portion of the ile.

t. A reinforced concrete pile for marine f Work barring a plurality of longitudinali `disposed metal reinforein members exten e ing longitudinally tbereo said reinforcing members being inwardly bent or dedected at a point below tbe part of the pile expoeed when n situ and the upper part of the pile being thickened or enlarged so that the arts of the reinforcing members above such end i and in tbe part of the ile above low water are more deeply embe ded in the concrete and protected by a thicker layer of concrete then are the parts of the reinforcing memblrs in the lower submerged portionof the p e.

- In testimony that l claim the foregoing as my own, l eHix my signature. 

